A Shunt is a precision-manufactured measuring resistor used for the indirect measurement of electric currents. Instead of measuring the current directly, the voltage drop that occurs when current flows through a defined resistor is measured. Using Ohm’s law, the actual current value can be calculated precisely from this voltage.
Current measurement using a shunt is one of the most commonly used methods in electrical measurement technology, as it is precise, reliable, and relatively easy to implement.
How does a shunt work?
If a shunt resistor is connected in series with a load, all of the current flows through that resistor. This results in a small voltage drop that is proportional to the current.
The calculation is based on Ohm's law:
U = R × I
The following applies:
- U = Voltage drop across the shunt
- R = Resistance value of the shunt
- I = Current
If a measurement system measures the voltage across the shunt, the corresponding current value can be calculated automatically.
Example
A shunt with a resistance of 0.1 Ω produces a voltage drop of: at a current of 10 A
0.1 Ω × 10 A = 1 V
If this voltage is measured, the measuring system can use it to determine the current of 10 A.
Advantages of Current Measurement Using a Shunt
Shunt resistors offer numerous advantages:
- High measuring accuracy
- Simple integration into existing systems
- Low costs
- High long-term stability
- Suitable for DC and AC applications
- Wide measurement ranges thanks to different shunt designs
- Fast and Accurate Signal Processing
That is why shunts are used in laboratories, test benches, energy monitoring systems, battery tests, and industrial measurement systems.
Shunts in Measurement and Testing Technology
In modern measurement applications, currents ranging from a few milliamps to several thousand amps are often measured. The selection of the appropriate shunt depends on various factors:
- Measurement range
- Accuracy Requirement
- Power Dissipation
- Temperature Behavior
- Environmental Conditions
- Dynamic Range of the Measurement Signal
To ensure precise measurement results, shunt resistors must have a precisely known resistance value and exhibit as little temperature dependence as possible.
Shunt Measurement with Delphin Data Acquisition
The measurement data acquisition and data logging systems from Delphin Technology enable the precise measurement of current signals via shunt resistors. Users can select suitable external shunts based on their measurement task and integrate them into the measurement setup. The devices measure the voltage drop with high precision and automatically calculate the corresponding current value from it. In addition, the Delphin systems support the simultaneous measurement of other parameters such as voltage, temperature, frequency, vibration, or process signals, enabling complex test and monitoring tasks to be carried out efficiently.
The combination of flexible sensor connectivity, high-performance measurement hardware, and comprehensive analysis software makes it possible to reliably visualize, store, and evaluate current measurements. [delphin.de], [delphin.de]
Typical Applications of Shunts
- Energy and Load Analyses
- Current and Power Monitoring
- Battery Testing and Energy Storage Systems
- Test stands
- Power Supply Design
- Equipment Monitoring
- Electric Mobility
- Industrial Automation
- Research and development